Bulletin No. 35. 118 



time and thought to the work. There are many pleasures con- 

 nected with gardening, even under the somewhat trying condi- 

 tions of southern Arizona. 



CLASSES OF VEGETABLES. 



In respect to their relation to temperature, vegetables may be 

 divided into three fairly distinct classes: ( 1 ) those that thrive 

 only during cool and moderately cool weather, and endure tem- 

 peratures as low as 15 to 20 deg. F., (2) those that grow well only 

 during moderately warm weather and do not endure temperatures 

 below 30 deg. to 32 deg. F. , and (3) those that thrive only dur- 

 ing warm or hot weather. 



To the first class belong the beet, cabbage, carrot, cauliflower, 

 endive, kohl rabi, lettuce, parsley, parsnip, radish, salsify, spin- 

 ach and turnip. It will be seen that, with the exception of cauli- 

 flower, the list includes only those vegetables of which the leaves 

 or roots are eaten. All of these can be grown in southern Ariz- 

 ona during autumn, winter and early spring, but cannot be suc- 

 cessfully grown during the heat of summer. They do best if put 

 out during September and October, or during January and Feb- 

 ruary. 



The second class includes beans, peas, potatoes and tomatoes, 



vegetables grown during spring and during early autumn. The 

 vegetative part of peas endures most of the low temperatures of 

 our region, but the blossoms and young pods are quite sensitive 

 to frost. Tomato plants usually remain alive during the heat 

 of summer, but in the warmest parts of southern Arizona produce 

 little or no fruit. Vegetables of this class must be planted so as 

 to make their growth between the frosts of winter and the extreme 

 heat of summer. 



To the third class mentioned belong corn, cucumbers, egg- 

 plant, melons, peppers, sweet potatoes, pumpkins and squashes, 

 including, with the exception of sweet potatoes, only those vege- 

 tables of which the fruit (that is, the seed-bearing part) is used for 

 food. These thrive during summer. Corn, however, might more 

 appropriately be placed in the second class, since the seed produc- 

 ing organs are injured by the extreme heat of summer, in some 



